Natalia Potanina was married to Potanin for 30 years and they
have three children together. They divorced in 2014.

Potanin claims to have offered her a £32 million ($49 million)
settlement last year, as well as a portfolio of properties in
Moscow, London and New York, and a monthly allowance of $250,000
(£163,496).

But his former wife denied she ever received such an offer.
Potanina claims she was only offered medical coverage, some
security expenses and one house in Moscow,
according to the Daily Mail.

Potanina claims she's owed a lot more. Under Russian law, wealth
acquired during marriage is split equally. Potanina filed a
petition to this effect at Moscow's Presnensky District Court
last year.

The petition includes a claim for 50% of his shares in the
world's biggest nickel producer, Norilsk Nickel, which has a
market value of $30 billion (£19.6 billion). Potanin owns 30% of
the nickel giant through his investment company Interros
International.

The case has now reached US courts. Potanina told CNN that she
was "forced" to involve the overseas courts in her divorce claim,
after she dragged a couple of US citizens into the case to give
evidence over how much money her former husband is allegedly
hiding away.